Studies of oxidized carbon nanotubes in temperature range RT–630 °C by the infrared and electron spectroscopies

The oxidized multiwall carbon nanotubes, their temperature modification in the range from RT to 630 °C are studied. The oxidation proceeds in aqueous solution of the concentrated HNO3. The oxidized multiwall carbon nanotubes are investigated using the infrared and electron spectroscopy methods.The oxidation creates mainly carboxyl, hydroxyl and carbonyl groups attached to multiwall carbon nanotubes, which can be detected by the infrared spectroscopy and at the surface by the electron spectroscopy methods. Thermal modification under ultra-high vacuum conditions leads to decreasing content of water, oxygen and carbon groups proceeding with different rates, increasing content of C sp2 bonds (e.g. carbon nanotubes reconstruction), surface atoms ordering and changes of surface atomic density.